Seedling watering question

Hi all,

My plants seem to die during the seedling stage pretty often, and my guess is that it has to do with watering.

During the seedling stage, I have them in red Solo cups under a 6500k CFL in Foxfarm Seed Starter soil. My question is - at this early stage, how much water should I use? A cup? 2 cups? etc.

Also, I am going to start using a moisture meter. Do I just water as soon as it shows the soil is dry? Or should I wait a day or 2 after it shows as dry?

Thanks in advance!

What i do in seedling stage is get a spray bottle and give them like 10 sprays or something (there in very small pots) and i do that twice a day